title: Application of 13C stable isotope labeling liquid chromatography-multiple reaction monitoring-tandem mass spectrometry method for determining intact absorption of bioactive dipeptides in rats.
abstract: The liquid chromatography-multiple reaction monitoring-tandem mass spectrometry (LC-MRM-MS/MS) method using (13)C stable isotope-labeled dipeptides was newly developed to simultaneously determine the absorption of three antihypertensive peptides (Val-Tyr, Met-Tyr, and Leu-Tyr) into blood of spontaneously hypertensive rats in one run-in assay. After extracting (13)C-labeled peptides in blood sample with a C(18) cartridge, the extract was applied to a (13)C monoisotopic transition LC-MRM-MS/MS system with D-Val-Tyr included as internal standard. An excellent separation of each dipeptide in LC was achieved at the elution condition of 5-100% methanol in 0.1% formic acid at a flow rate of 0.25 ml/min. The (13)C-labeled peptides ionized by electron spray were detected in the positive ion mode within 15 min. The established method showed high reproducibility with less than 10% coefficient of variation as well as high accuracy of more than 85%. After the administration of a mixture containing the three (13)C-labeled dipeptides to rats at each dose of 30 mg/kg, we could successfully determine the intact absorption of each (13)C-labeled peptide with the maximal absorption amount of 1.1 ng/ml plasma for Val-Tyr by the proposed LC-MRM-MS/MS method.
authors.affiliation: Division of Bioscience and Bioenvironmental Sciences, Faculty of Agriculture, Graduate School of Kyushu University, Fukuoka, Japan.
authors.forename: Eduardo M N
authors.initials: EM
authors.lastname: Nakashima
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kudo
authors.forename: Yuri
authors.initials: Y
authors.lastname: Iwaihara
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Tanaka
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Toshiro
authors.initials: T
authors.lastname: Matsui
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000097:blood* / Q000737:chemistry; D002247:Carbon Isotopes / Q000097:blood / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods; D004151:Dipeptides / Q000097:blood* / Q000737:chemistry; D007553:Isotope Labeling / Q000379:methods*; D016014:Linear Models; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D017207:Rats, Sprague-Dawley; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000959:Antihypertensive Agents; D002247:Carbon Isotopes; D004151:Dipeptides